Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RADT 156 Equipment Operation > Exposure Charts to Fluoro > Flashcards

Exposure Charts to Fluoro Flashcards

1
Q

When should exposure charts be updated?

A

Annually or if there has been a change in processing equipment- speed of films/ devices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the main disadvantage of a fixed mA system?

A

as kV increases, contrast and resolution decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Fixed mA formula

A

2kVp X part cm + 30kVp = New kVp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Edison built 4 portables in what year?

A

1896

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Conventional fluoro uses what type of screen?

A

fluorescent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A flourescent screen in conventional fluoro converts ______ to ______?

A

photons to visible light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A flourescent screen in conventional fluoro creates a _______, which is a real time visible image.

A

hologram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Conventional fluroscopy created a high or low patient/viewer dose?

A

HIGH- flouro time was longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 tubes included in Image Intensified Fluoro?

A

Image intensifier, TV Camera Tube, Cathode Ray Tube (CRT/Monitor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 benefits of image intensified fluoro?

A

improved brightness levels, improved visual acuity/contrast, lower patient exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Glass Envelope is made of what?

A

pyrex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Input Phosphor screen is made of what?

A

Cesium Iodide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the input phosphor screen convert?

A

converts invisible photons entering image intensifier tube to visible light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the possible dimentions for a dual and tri focused input phosphor screen?

A

dual- 6-9”
tri- 4/7/10”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Photo Cathode is made of what in the image intensifier tube?

A

Antinomy Sulphite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does the photo cathode convert?

A

converts visible light to electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the charge of the electrostatic lenses?

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do the electrostatic lenses do?

A

focus electrons from input screen to output screen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the electron focal spot?

A

point that electrons crossover and intersect during travel inside the tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When does the electron focal spot change?

A

when kV changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Output phosphor screen is made of what?

A

Zinc Cadmium Sulfide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does the output phosphor screen convert?

A

electronic image back to visible image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the normal size of the output screen?

A

1in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the purpose of the aluminum filter?

A

prevents light that bounces back from going into tube: MIRROR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How many times brighter is the image coming from image intens fluoro compared to conventional?

A

5,000-10,000 times brighter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the brightness gain formula?

A

BG= Flux Gain X Minification Gain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the definition of flux gain?

A

gain in brightness from tube potential- as kV increases, brightness and flux gain increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the definition of minification gain?

A

ratio of input screen (squared) : ratio of output screen (squared)
ex: 9^: 1^

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Definition of contrast resolution

A

ability to see differences in densities and tissue opacities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Definition of spatial resolution

A

ability to discern between line pairs/ structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

As size of input screen _______, spatial resolution _______

A

increases, decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

As size of input screen __________, vignetting ___________

A

increases, increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Definition of vignetting

A

reduced brightness/ blur at image periphery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Definition of Automatic Brightness Control

A

maintains image quality/ brightness when part thickness changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the line pair/ mm spatial resolution for a 9” input screen?

A

1-2 line pairs/ mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the line pair/ mm spatial resolution for a 4” input screen?

A

6 line pairs/ mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Image quality in a fluroscopic image refers to what 2 traits?

A

resolution and magnification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Small Field size in image intens fluoro gives what 3 image quality traits?

A

improved magnification
improved resolution
increased patient dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Higher kv in image intens fluoro gives what 3 image quality traits?

A

improved magnification
improved resolution
greater image brightness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Higher mA in image intens fluoro gives what 3 traits?

A

higher resolution
greater brightness
increased patient dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does the TV camera tube convert?

A

visible light to synchronous modulated signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is included on the target assembly end of the tv camera tube? (2)

A

Photocathode & Signal Plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

The photocathode is made of what in a tv camera tube (target assembly)

A

antinomy trisulfide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Signal plate is composed of what?

A

thin graphite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What does the signal plate in the tv camera tube do?

A

conducts electrical impulses which will be converted to synchronous modulated video signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

The opposite side of the target assembly in a tv camera tube contains what? (3)

A

Electron Gun, Steering Coils, Accelerator Grids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the electron gun composed of?

A

heated filament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What does the electron gun do?

A

directs electrons into raster pattern onto target surface to produce video signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What type of charge do the steering coils have?

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the purpose of the accelerator grids?

A

provide electrical potential to accelerate electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

The TV monitoring system (CRT) contains what 4 parts?

A

Gas Evacuated Tube
Electron Gun
Focusing and Deflecting Coils
Fluorescent Screen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What part of the TV monitoring system creates the image that is seen on the TV monitor?

A

fluorescent screen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What creates 1 Frame?

A

2 Horizontal Lines (1 Field) & 2 Vertical Lines (1 Field)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the difference in spatial resolution (lines) between standard tv and digital fluoro

A

525 vs 1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Definition of vertical resolution

A

number of lines per frame

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Definition of horizontal resolution

A

frequency/ how often beam is changed- measured in Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Horizontal resolution/bandwith for commercial TV

A

3.5 MHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Horizontal resolution/bandwith for fluoro TV

A

4.5 MHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Horizontal resolution/bandwith for digital fluoro

A

20 MHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

In a TV Monitor viewing system, what is placed between the image intensifier tube and tv camera tube?

A

coupled device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the purpose of the coupled device?

A

transfers and magnifies images from the intensifier tube to an optimal viewing device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

3 ways in which coupling devices may be used

A
  1. Mirror Optical Viewing System
  2. Tandem Mirror Device (beam splitter)
  3. Fiber Optics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is a lens coupling device?

A

system of mirrors positioned to divert beam to viewing device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

How does a tandem mirror device function? (beam splitter)

A

tv systems are used to record image directly off image intensifier tube - beam goes in multiple directions
10-90% goes to TV Camera Tube
Other goes to TV Monitor or Recording Device

65
Q

What are the 5 disadvantages of a fiber optic viewing device?

A

expensive
without video or viewing camera
limited fluoro viewing
cannot accommodate imaging devices
images can only be viewed and NOT recorded

66
Q

What are the advantages of a TV Monitoring system?

A

Brightness & contrast can be manipulated
Multiple viewers
Multiple recording systems can be integrated
Digital imaging is possible

67
Q

In digital fluoro, what is inserted between the video signal and tv monitor?

A

computer

68
Q

What replaces the TV Camera tube (in imag intens), in digital fluoro?

A

Charged Coupling Device

69
Q

What is the charged coupling device composed of?

A

crystalline silicon

70
Q

What does the charged coupling device convert?

A

visible light to electrons

71
Q

What is the spatial resolution of digital?

A

10 lp/ mm

72
Q

In a digital video system, how long does it take for the beam of the tv camera tube to sweep the target assembly?

A

33msec= 1 frame

73
Q

Signal to noise ratio: higher ratio = ______ noise

A

less

74
Q

The analog digital converter (ADC) increases in bits, there are more signal values which creates greater ________ & ________

A

densities and resolution

75
Q

Regarding data aquisition, as the matrix size _____, data aquisition ______

A

increases, decreases
as the resolution increases we can acquire less data

76
Q

Digital fluoro allows these 3 different types of subtraction techniques as a great advantage

A

Temporal, Energy, Hybrid

77
Q

Temporal subtraction in digital fluoro does what?

A

frame 1 is subtracted from subsequent frames to change densities/ contrast

78
Q

Energy subtraction in digital fluoro does what?

A

removes a select spectrum of energy from K-shell absorption (photoelectric effect)

79
Q

What is the greatest advantage of digital fluoro?

A

pulsating x-ray beam breaks up beam into smaller dose decreasing patient exposure = more info in less fluoro time

80
Q

What is the spatial resolution of the PACS HR flat panel screens?

A

2000 lines/ frame

81
Q

The 3 phase high frequency generator of digital fluoro creates what bandwidth?

A

90hZ (per sec)

82
Q

What is the output phosphor made of?

A

zinc cadmium sulfide

83
Q

Output phosphor converts ____ to ____

A

electron image back to visible light

84
Q

What kV does the image intensifier tube usually run at?

A

80 kVp

85
Q

What is the minimum required kV for the image intensifier tube to function

A

25 kV

86
Q

What is placed at the back of the output phosphor to reduce bounceback of light

A

aluminum filter

87
Q

brightness gain for image intensifier when compared to conventional fluoroscopy

A

5000 - 10,000 times brighter

88
Q

formula for brightness gain

A

BG = flux gain x minification gain

89
Q

formula for flux gain

A

tube potential (kV)

90
Q

formula for minification gain

A

input screen : output screen squared ( 9^2 / 1^2 for 9 inch input and 1 inch output)

91
Q

What is the standardized unit for brightness gain?

A

Conversion factor = Candela per meters squared / mR per second

92
Q

9” input screen creates how many line pairs per mm

A

1 - 2 lp mm

93
Q

4” input screen creates how many line pairs per mm

A

6 lp mm

94
Q

As input screen size goes up, spatial resolution goes ___

A

down

95
Q

Input screen size goes up, vignetting ___, brightness ___

A

vignetting increases, brightness decreases

96
Q

what is vignetting

A

reduced brightness / blur at the image periphery

97
Q

what maintains image quality / brightness when part thickness changes

A

automatic brightness control

98
Q

as input screen size decreases, magnification ____

A

increases

99
Q

as input screen size decreases, resolution ___

A

increases

100
Q

as input screen size increases, exposure rate and dose ____

A

decreases

101
Q

as kV is increased, magnification ____

A

increases

102
Q

as kV decreases, resolution ____

A

decreases

103
Q

as kV increases, image brightness _____

A

increases

104
Q

as mA increases, resolution ____

A

increases

105
Q

as mA increases, image brightness _____

A

increases

106
Q

as mA decreases, patient dose ____

A

decreases

107
Q

How does the electron focal spot move when kV is increased?

A

focal spot moves closer to the input screen

108
Q

What happens when the electron focal spot moves closer to the input screen?

A

increased magnification, bightness, and resolution (loss of periphery due to divergence)

109
Q

3 types of TV Camera tubes

A

vidicon, plumbicon, orthicon

110
Q

The photocathode in the target assembly (TV camera tube) converts ___ to ____

A

visible light to electrons

111
Q

the signal plate in the target assembly (TV camera tube) converts

A

electrical impulses into a synchronous modulated video signal

112
Q

frequency of the synchronous modulated video signal at the end of the TV camera tube

A

60 Hz

113
Q

what comes out of the TV camera tube

A

synchronous modulated video signal

114
Q

raster pattern in the CRT

A

like a typewriter, 2 horizontal traces and 2 vertical traces from electron gun make up 1 TV picture frame

115
Q

how many scanned lines are in 1 field of a raster pattern?

A

262.5 scanned lines in 1/60 of a second

116
Q

____ fields make up 30 frames

A

60 fields

117
Q

How many scanned lines appear every 1/30th of a second

A

525 lines, creating 2 interlaced fields

118
Q

2 interlaced scanning fields creates ___ frames

A

1 frame

119
Q

In digital progressive mode, how long does it take the target assembly to sweep from top to bottom?

A

33 msec or 0.033 sec

120
Q

Number of lines of active trace per frame in standard TV

A

525 lines

121
Q

Number of lines of active trace per frame in Digital Fluoro

A

1000 active lines

122
Q

vertical resolution equals

A

lines per frame

123
Q

horizontal resolution equals

A

frequency in Hz, which is times per second the beam is modulated

124
Q

definition of noise

A

undesirable fluctuations in densities

125
Q

causes of noise in digital fluoroscopy

A

fluctuations in voltage, differences in heating of filaments, interruption of a signal

126
Q

signal to noise ration - higher ratio equals ____ signal and ____ noise

A

high signal and less noise - which is good

127
Q

most common type of viewing system

A

TV monitoring - closed circuit with coupling devices between image intensifier and TV monitor

128
Q

Lens coupling device converts

A

light from image intensifier to parallel beam to divert

129
Q

disadvantages of lens coupling

A

limited viewing, single viewer, viewing one image at a time

130
Q

charged coupling device is made of

A

crystalline silicon

131
Q

charged coupling device converts

A

visible light to electrons

132
Q

matrix size of a charged coupling device

A

1024 x 1024 pixels

133
Q

resolution of digital charged coupling device

A

10 line pairs per mm

134
Q

benefits of charged coupling device

A

high resolution, linear contrast so no densities are useless, no distortion artifacts

135
Q

what is the weakest link with the weakest signal in the TV imaging chain

A

CRT

136
Q

matrix size of digital fluoroscopy

A

1024 x 1024

137
Q

1024 x 1024 is also known as

A

1000 line system

138
Q

pixel size =

A

image intensifier size in mm / matrix size by 1 way (127 mm divided by 1024 = 0.124mm pixel size)

139
Q

A high frequency generator for digital fluoro operates at ___ Hz

A

90 Hz instead of the traditional 60

140
Q

how much mA does image intensified fluoroscopy typically use

A

5 mA

141
Q

how much mA does digital fluoroscopy typically use

A

hundreds of mA

142
Q

benefit of pulse progressive fluoroscopy

A

reduced heat overload

143
Q

Charged coupling device replaces the

A

TV tube

144
Q

How does the analog to digital converter create a video signal?

A

creates a binary numeric value to represent a density for transmitting to each pixel on the monitor

145
Q

Digital image acquisition can take ___ images per second

A

1-10 images per second

146
Q

How long does digital image acquisition take to produce 1 video frame?

A

33 ms or 0.033 sec

147
Q

long exposures ___ patient dose and ___ noise

A

increase, increase

148
Q

microprocessor (computer) image quality depends on

A

speed of image acquisition, image processing, post manipulation processing

149
Q

what is the range of moving images and information

A

systemic dynamic range

150
Q

Meaning of ADC

A

analog to digital converter

151
Q

8 bit ADC = ___ analog signal values

A

0 - 255

152
Q

10 bit ADC = ___ analog signal values

A

1023

153
Q

As ADC bits increases, resolution ____

A

increases

154
Q

Output of ADC is transmitted and manipulated into ___

A

pixel and matrix form

155
Q

image acquisition, processing, and transmission depend on

A

dynamic range of pixels, number of pixels, method of storage

156
Q

How many images per second can data acquisition get

A

30 images per second

157
Q

As pixel matrix size increases, data acquisition ____

A

decreases

158
Q

How many images per second can a 1024 matrix acquire?

A

8 images per second

159
Q

PACs stands for

A

picture archival communication systems

RADT 156 Equipment Operation (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions